How to test presence of dead pixels on your LCD

[Abel18]

We know, LCDs are fragile and their design imperfect. It is quite common that when one buys a laptop, its screen is decked out in one or more "Dead pixels". A defect often seen as normal by the manufacturers, but sometimes very debilitating! Dead Pixel Buddy can screen and test the operation of each sub-pixel.

Thanks to this utility can request a exchange under warranty. LCD is made up of dots (pixels), themselves formed by 3 sub-pixels (one blue, one red and one green). It may happen that one of the transistors that activates the light of a sub-pixel is defective (either original or with time). Therefore, the color emitted by the point (formed by 3 sub-pixels) is incorrect. This is what is called a "Dead pixel".

LCDs are relatively fragile and delicate design. And indeed, it is quite common at the time of purchase, the screen of a laptop features already one or more "Dead pixels". While the number of dead pixels is limited, the defect is considered "Normal" by manufacturers. However, today, manufacturers and retailers begin to offer a guarantee to deal with this problem ... Some builders even now guaranteeing their computer screen "100% no dead pixel". But it is not always easy to detect corrupted pixels!

The small free program Dead Pixel Buddy is there for that. You can test the screen and the operation of each sub-pixel successively displaying a white screen, black, red, green and blue. If you see an abnormal number of faulty pixels on your laptop brand new, so you can easily prove your allegations and request an exchange under warranty.

[Abel18]

The software requires no installation. It can be easily launched from a USB key, which can test the screen directly in the store example.

At launch, Dead Pixel Buddy on the left shows seven large buttons, including six former serves to highlight the shortcomings of each sub-pixel:

• BLACK: Displays the entire screen black ... If an item is displayed in a lighter color is a dead pixel.
• WHITE: Turns all sub-pixels. Any item appearing other than white is defective.
• RED: Testing all sub-pixels RED ... The sub-pixel defect appear in another color
• GREEN: Testing all sub-pixels GREEN. If a pixel appears in another color, it is defective.
• BLUE : Testing all sub-pixels BLUE. If a pixel appears in another color, it is defective.
• CUSTOM: Test any color, ie any combination of values of sub-pixels. Useful if you have any doubt in spite of previous tests.
• The last button, Cycle Time, Is used to cycle through colors automatically by specifying the display time (in seconds) of each color.